This core facility will provide the high quality flow cytometry and sorting required by all four of the projects outlined in this proposal. The facility has a dedicated operation who will maintain and operate three instruments. An advanced MoFlo will be used for sterile sorting of single cells or bulk populations. It will be configured with two lasers or UV and visible applications, as well as six fluorescence detectors to allow multiparameter resolution and sorting of up to four populations simultaneously. A FACScan and a FACSCalibur will yield analytical flow cytometry data as required for many of the proposed experiments.